Answer:
posting vacation photos while you are away
Step-by-step explanation:
When you post a vacation photo showing that you and your family (or you alone if you live alone) are having fun somewhere, you are showing that your house is unoccupied, there is no one in the house, because all residents are enjoying their vacation, so you're showing that your home may be unattended.
In summary, posting vacation photos while you're away is a social media post that indicates that your home may be unattended.